This invention relates to a process and apparatus for regenerating - rejuvenating and uniformly distributing catalyst in a slurry phase reactor by using a substantially vertical draft tube means, open at both ends, fully immersed in the slurry in said reactor and utilizing rejuvenating gas injected at or substantially near the bottom of said draft tube means through hydrogen gas injection means. Catalyst is drawn up the draft tube means from near the bottom of said reactor under the influence of the rejuvenating gas and ejected from the top of the draft tube means at or below the top of the slurry phase in such reactor. Catalyst reactivation - regeneration is accomplished using the draft tube means by using a rejuvenating gas such as hydrogen. For the purpose of this specification, draft tube means will be referred to variously as draft tube, draft tubes, rejuvenation tube or rejuvenation tubes according to the context of the specification, unless otherwise indicated.
Slurry reactors are well known for carrying out highly exothermic, three phase, catalytic reactions. Usually called xe2x80x9cbubble columnsxe2x80x9d these reactors have a liquid phase in which solid catalyst particles are dispersed or held in suspension by a gas phase bubbling through the liquid phase, thereby creating a slurry. These reactors provide improved heat transfer characteristics for the exothermic reaction, with the bubbling gas maintaining the catalyst as a dispersion in the liquid phase.
Bubble column reactors typically have a multiplicity of tubes suspended within a shell-type housing, the tubes being filled with a heat transfer medium, e.g., boiling water, which absorbs the heat generated by the exothermic reaction occurring on the shell side of the tubes in the main body of the housing.
Alternatively the reactor can be of a similar multitube design housed in a common shell-type housing as previously described but wherein the gas and liquid are passed through the multiple tubes which function as the reactor tubes, with effluent being removed from the upper ends of the reactor tubes and heat transfer fluid being passed through the space along the outside surfaces of the reactor tubes. The reactor tubes can be either multiple individual tubes with spaces between adjacent tubes, or multiple bundles of tubes with spaces between adjacent bundles of tubes.
Likewise the entire cross section of the reactor vessel may have a plurality of shafts disposed within it, the bottoms of said shafts being located above the reaction gas inlet but extending a distance above the top surface of the reaction slurry into the gas disengaging spaces so as to create multiple single columns of standing, noncirculating liquid with catalyst suspended and dispersed in said standing liquid. The reaction zone therefor has multiple single columns, said columns having a common bottom reaction gas introduction zone and a common upper gas disengagement space. To insure proper control of the exothermic process additional tubes can be inserted into or between the multiple single columns to function as heat exchangers.
It would be an advance if, in whatever configuration the reaction vessel may take, catalyst within the reaction vessel could be more uniformly distributed and circulated so as to insure more even catalyst aging in the course of the reaction, more effective use of the catalyst by insuring a higher probability that the maximum amount of available catalyst is in the reaction zone to promote the reaction by eliminating stagnant zones of uncirculating, standing catalyst, decreasing mass transfer limitations, and improving heat transfer utilization.